One hundred years from now, challenges await genealogist Melanie Arscott's successor.
Monday marks the start of census season, with Canadians starting to receive the 2011 short-form questionnaire and the new National Household Survey.
"We rely on vital statistics and census information to tell us about the people and the places in our family's history. And when those details are not available it's what we call 'hitting a brick wall,'" Arscott said about the impact the voluntary NHS will have as it replaces the mandatory long-form census of years past.
Arscott, president of the Victoria Genealogical Society, says the more in-depth information, which has been collected in some form since confederation in 1867, is essential.
"It has more information just about the people and the way they live... It's so much more than just a number," she said, about what the compulsory short-form census will now provide.
Because the NHS is voluntary, even Statistics Canada, which administers the census, is doubtful it will see a strong return of the surveys.
"With ... an anticipated response rate of 50 per cent, approximately 16 per cent of the Canadian population will complete the National Household Survey, compared with 19 per cent under a mandatory census long form," read an October StatsCan release.
"Given its anticipated lower overall number of respondents, the National Household Survey will ... have a sampling error that is slightly higher (worse) than would have been achieved from a mandatory long-form census."
The NHS will be mailed to one-third of all Canadian households by the end of May. But many people say the anticipated 50 per cent return estimate is high.
"Even the people who manage and operate the National Household Survey within StatsCan are uncertain of the outcome and impact it's going to have," said Eric Sager, professor of history at the University of Victoria. "My predication is that when the results of the NHS come in, it's going to lead to debate, continuing argument and uncertainty over the quality and reliability of the data gathering."
The problem, Sager says, is selection bias. Certain demographics – middle- to high-income earners, those with higher education, Canadians who've lived at the same place for a long time – will be more likely to respond to a voluntary survey than other, more vulnerable people, who are ultimately expected to be underrepresented by the NHS.
Census data from the late 1800s and early 1900s has been an integral part of Sager's studies for more than two decades. He is one of the leaders on the Canadian Century Research Infrastructure project, documenting societal changes after the turn of the century.
"It reflects the fact that the census information is the most important single source we have on the Canadian people and Canadian population," he said. "I would not want to be a historian of Canada's population a century from now. All the work I've done would be impossible."
Reliable census data is useful in the short-term as well. Cities and municipalities use it on a constant basis when making planning and financial decisions.
"It seems to touch just about every department we've got," Saanich Mayor Frank Leonard said. "This new information (from the NHS) won't be as valid because it won't be scientific ... I can't think of a decision that we would make different because that data is not going to be scientifically valid – it's just not going to give us as much comfort."
Last summer, the federal Conservative government announced it was scrapping the mandatory long-form census due to privacy concerns.
"In the past, the Government of Canada received complaints about the long-form census from citizens who felt it was an intrusion of their privacy," said industry minister Tony Clement in July. "The government does not believe it is appropriate to force Canadians to divulge detailed personal information under threat of prosecution."
Sager says those concerns are fallacious, adding that the information is scanned by computers. The only time your individual responses will be seen is 92 years from now, when it becomes available to family members and historians.
Arscott says all that she can do is urge people to fill out the voluntary forms and allow the information to be available in 2103.
"As we go forward and find that information is restricted and sanitized, we're going to have less and less to work from," she said. "Right now, when we're looking for information, we're looking for a needle in a haystack. This is making the haystacks bigger and the needles smaller."
Census data
• Census forms are due back by July 29
• Aggregate information releases will begin starting in late 2011 through October 2012
• Two new questions will be on the mandatory short-form census, pertaining to languages (fluency in English and French, and languages spoken at home)
• Not filling out your form or providing false information on your census can lead to a $500 fine, imprisonment for up to three months, or both